Abstract: In a wave focusing device and a wave emitting device having the wave focusing device, the wave focusing device has a plurality of filters and focuses a wave by a phase overlap. The plurality of filters includes a first filter formed on a substrate, a second filter formed on the substrate and overlapping with the first filter in a first area, and a third filter formed on the substrate and overlapping with the second filter in a second area. A size of the first area is substantially same as that of the second area. A first portion of the second filter in the first area is inverted to a second portion of the second filter in the second area, with respect to a first axis. A wave passing through the wave focusing device is focused at a center of each of the first, second and third filters.

Abstract: A message server and a message processing apparatus including the same are provided. According to the embodiments of the present disclosure, when the device management module is not available to be used, a message is directly delivered to the application client through the third party message server so that the reliability of the message forwarded between a sender side and a receiver side can be ensured.

Abstract: A device-to-device (D2D) communication method is provided. According to an inventive concept, the method comprises, storing, by a first device, first authentication data including a hash chain, which is a sequential concatenation of hash values, and storing, by a second device, second authentication data including an initial hash value of the hash chain, transmitting, by the first device, a final hash value of the hash chain to the second device, determining, by the second device, whether authentication between the first and second devices has succeeded by repeatedly hashing the initial hash value stored in the second device until a hash value identical to the final hash value is returned, and if a determination is made that authentication between the first and second devices has succeeded, performing, by the first and second devices, a connection establishment process for establishing a connection between the first and second devices.

Abstract: A message server and a message processing apparatus including the same are provided. According to the embodiments of the present disclosure, when the device management module is not available to be used, a message is directly delivered to the application client through the third party message server so that the reliability of the message forwarded between a sender side and a receiver side can be ensured.

Abstract: A device-to-device (D2D) communication method is provided. According to an inventive concept, the method comprises, storing, by a first device, first authentication data including a hash chain, which is a sequential concatenation of hash values, and storing, by a second device, second authentication data including an initial hash value of the hash chain, transmitting, by the first device, a final hash value of the hash chain to the second device, determining, by the second device, whether authentication between the first and second devices has succeeded by repeatedly hashing the initial hash value stored in the second device until a hash value identical to the final hash value is returned, and if a determination is made that authentication between the first and second devices has succeeded, performing, by the first and second devices, a connection establishment process for establishing a connection between the first and second devices.

Abstract: A method of manufacturing a wire grid polarizer includes: preparing a stamp having a nanostructure body at one surface and forming a mask layer with anisotropic vapor deposition at the one surface; forming a metal film on a substrate; transferring a mask layer of an upper portion of a nanostructure body in the mask layer onto the metal film; and patterning the metal film into metal lines by removing a portion that is not covered with the mask layer in the metal film with dry etching.

Abstract: A method of manufacturing a wire grid polarizer includes: preparing a stamp having a nanostructure body at one surface and forming a mask layer with anisotropic vapor deposition at the one surface; forming a metal film on a substrate; transferring a mask layer of an upper portion of a nanostructure body in the mask layer onto the metal film; and patterning the metal film into metal lines by removing a portion that is not covered with the mask layer in the metal film with dry etching.

Abstract: A method of manufacturing a wire grid polarizer includes: preparing a stamp having a nanostructure body at one surface and forming a mask layer with anisotropic vapor deposition at the one surface; forming a metal film on a substrate; transferring a mask layer of an upper portion of a nanostructure body in the mask layer onto the metal film; and patterning the metal film into metal lines by removing a portion that is not covered with the mask layer in the metal film with dry etching.